A large variety of polymeric materials which are utilized as the resinous component both in coating compositions and molding compositions for molded plastics are light sensitive, hence they must be protected from ultraviolet light in order to prevent degradation of the polymer in the final product. Typically, materials known as ultraviolet light stabilizers are incorporated into the coating or molding composition to inhibit the effects of ultraviolet light. A particularly well known and effective group of such materials are sterically hindered piperidine compounds, for example, materials containing the moiety 2,2,6,6-tetramethyl piperidine. However, sterically hindered piperidines of this type readily elute from the composition containing them, and in addition, they pose problems in handling and use. Moreover, coatings containing them have a tendency to exhibit blooming.
To overcome these difficulties, efforts have been directed toward chemically incorporating the ultraviolet light stabilizer into the polymeric backbone of the material to be protected. For example, U.S. Pat. No. 4,102,870 to Hoffman is directed to a manner of chemically incorporating hindered piperidine derivatives into a thermoplastic polyurethane polymer and U.S. Pat. No. 4,234,728 to Rody et al deals with the chemical incorporation of hindered piperidines into thermosetting compositions. The manner of incorporating the substituted piperidine moiety into thermosetting compositions is not easily accomplished and in addition can be relatively expensive. There is a need, therefore, for a simple, economical manner of incorporating ultraviolet light stabilizers into thermosetting compositions, particularly aminoplast curable compositions.